Funding for this research was provided by:
Key Project of National Natural Science Foundation of China (8177060452)
Key Research and Development Project of Science and Technology Department of Sichuan Province (2017SZ0067)
1.3.5 project for disciplines of excellence, West China Hospital, Sichuan university (ZY2016104)
Text and Data Mining valid from 2020-03-23
Received: 17 May 2019
Accepted: 17 February 2020
First Online: 23 March 2020
Ethics approval and consent to participate
: This study was approved by the Biomedical ethics committee, west China hospital, sichuan university (2018–256). The research was a retrospective study, and all data were collected from the hospital information system, and we have applied for exemption from informed consents. Because of the retrospective nature of the study, patient consent for inclusion was waived.
: Not applicable.
: The authors declare that they have no competing interests.